参考代码
Select Case e.DataCol.Name
Case "现金收入", "现金支出"
For Each dr As DataRow In e.DataTable.Select("[日期] >= #" & e.DataRow("日期") & "#")
Dim Val1 As Double = e.DataTable.Compute("Sum(现金收入)","日期 <= #" & dr("日期") & "# and [_Identify] <= " & dr("_Identify"))
Dim Val2 As Double = e.DataTable.Compute("Sum(现金支出)","日期 <= #" & dr("日期") & "# and [_Identify] <= " & dr("_Identify"))
dr("余额") = Val1 - Val2
Next
End Select